An ab initio computational study on selected lycopene isomers

Gregory A. Chasse, Melody L. Mak, Eugen Deretey, Imre Farkas, Ladislaus L. Torday, Julius G. Papp, Dittakavi S.R. Sarma, Anita Agarwal, Sujatha Chakravarthi, Sanjiv Agarwal, A. Venket Rao

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69 Citations (Scopus)


Lycopene is an effective antioxidant in vivo. Although lycopene is present in its all-trans isomeric form in fruits and vegetables, serum and tissue samples show a predominance of various cis-isomers of lycopene. The present study was undertaken to investigate the molecular structure of several cis-isomers of lycopene using an ab initio molecular modeling procedure. The relative stability of selected cis-isomers of lycopene with respect to the all-trans isomer, was studied. The following sequence of stability was observed. 5-cis > all-trans > 9-cis > 13-cis > 15-cis > 7-cis > 11-cis. The first four of these isomers had relative energies within +1 kcal mol-1, but the fifth isomer (i.e. 15-cis) was within 3 kcal mol-1. However, the last two isomers were less stable than the all-trans-isomer with more than 5 kcal mol-1, difference in energy. The optimized molecular conformational study structures indicated that the central conjugated part of every lycopene isomer is planar. However, the two tail ends of the molecules, each containing three single C-C bonds, avoid coplanarity.

Original languageEnglish
Pages (from-to)27-37
Number of pages11
JournalJournal of Molecular Structure: THEOCHEM
Issue number1-3
Publication statusPublished - Aug 27 2001



  • Ab initio MO theory
  • All trans-lycopene
  • Computations of lycopene isomers
  • Selected cis-isomers of lycopene
  • Thermodynamic stability of lycopene isomers

ASJC Scopus subject areas

  • Biochemistry
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Cite this

Chasse, G. A., Mak, M. L., Deretey, E., Farkas, I., Torday, L. L., Papp, J. G., Sarma, D. S. R., Agarwal, A., Chakravarthi, S., Agarwal, S., & Rao, A. V. (2001). An ab initio computational study on selected lycopene isomers. Journal of Molecular Structure: THEOCHEM, 571(1-3), 27-37.